Which heavyweight do you consider to be the best balanced in terms of power and chin?

Tua, Tyson, and Marciano.

 

Out of that list, I'd lean toward Vitali Klitschko.

He had serious power, maybe not the one-punch eraser like Foreman or Tua, but heavy hands that broke guys down consistently, and easily one of the best chins ever at heavyweight. Never knocked down officially in his prime, never seriously hurt, even when he was older and facing bigger punchers. You could hit Vitali flush and he'd just absorb it and keep marching forward.

Foreman had bigger raw power, sure, but he was way more open defensively, and while his chin was very good, it wasn’t quite unbreakable, Ali wore him down, Lyle dropped him.
Tua had a rock chin too, but was smaller, less versatile, and his power didn't always show against the top heavyweights when he needed it most.
Liston’s chin is a little hard to fully gauge, he was durable but crumbled badly once fights turned against him.
Bowe could take insane punishment, but his defence was sloppy and he took too much unnecessary damage.
Tyson had huge power, no question, but his chin wasn’t as bulletproof as people sometimes remember once the mental side went, he could be worn down too.

Vitali combined power, durability, and mentality the most consistently. He didn’t have many glaring weaknesses once the bell rang, you had to beat him by injury or outworking him over the long haul, not by cracking his chin or overpowering him.